WASHINGTON - Some of the largest IT companies in India and the U.S. are complaining to President Obama that it has become increasingly difficult to get work visas for their employees -- and they want him to take action.

In a letter Thursday to Obama, the companies said that the U.S. is creating "unprecedented delays and uncertainty" around L-1 visas, which are used for intra-company transfers of employees from foreign offices to U.S. offices. They claim that U.S. immigration authorities are exceeding the law in rejecting their visa applications.

The White House letter sheds light on just who is behind this push to change how the U.S. treats visa applications.

Although the L-1 visa is different from the H-1B visa, they are part of the same debate concerning the displacement of U.S. workers by foreign labor. Critics contend that offshore companies, in particular, use the L-1 for the same reason they use the H-1B visa: to help move work overseas.

In recent years, the U.S. has toughened enforcement of its H-1B and L-1 program through rejections of visa petitions and increased demands for paperwork that can lengthen the wait, and cost, of a visa.

Complaints about the visa processes have been growing in recent years, and the undertone of the letter to Obama is one of frustration. "Such delays or denials do not enhance compliance or enforcement and do nothing except disrupt carefully-laid business plans and create significant costs to the company and the American economy," the companies told Obama.

Among the companies listed on the letter are major Indian offshore firms, including Wipro Technologies and Tata America International Corp. -- a subsidiary of offshore giant Tata Consultancy Services -- as well as firms that rely heavily on India and other countries for offshore labor, including U.S.-based Cognizant Technology Solutions and Accenture.

Other firms signing it included eBay, EMC, General Electric, Hewlett-Packard Co., Intel, Microsoft, Texas Instruments, as well as a number of firms in other industries, including Boeing, Dow Chemical, Caterpillar and Chevron USA. The U.S. Chamber of Commerce, along with numerous tech-related groups, signed it, too.

The lobbying effort has been largely behind-the-scenes, but its goal was outlined in a letter released earlier this month by the two leading congressional critics of work visa policies, U.S. Sens. Richard Durbin (D-Ill.) and Charles Grassley (R-Iowa).

In their letter to U.S. Citizenship and Immigration Service (USCIS) Director Alejandro Mayorkas, Grassley and Durbin said they were aware that the agency was considering making it easier for companies to transfer workers to the U.S. under the L-1B rules. The L-1 is the visa most commonly used.

"We are concerned that the L-1B program is harming American workers because some employers, especially foreign outsourcing companies, use L-1B visas to evade restrictions on the H-1B visa program," wrote Grassley and Durbin.